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//===- Interpreter.cpp - Top-Level LLVM Interpreter Implementation --------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the top-level functionality for the LLVM interpreter.
// This interpreter is designed to be a very simple, portable, inefficient
// interpreter.
//
//===----------------------------------------------------------------------===//
#include "Interpreter.h"
#include "llvm/CodeGen/IntrinsicLowering.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Module.h"
#include <cstring>
using namespace llvm;
namespace {
static struct RegisterInterp {
RegisterInterp() { Interpreter::Register(); }
} InterpRegistrator;
}
extern "C" void LLVMLinkInInterpreter() { }
/// Create a new interpreter object.
///
ExecutionEngine *Interpreter::create(std::unique_ptr<Module> M,
std::string *ErrStr) {
// Tell this Module to materialize everything and release the GVMaterializer.
if (Error Err = M->materializeAll()) {
std::string Msg;
handleAllErrors(std::move(Err), [&](ErrorInfoBase &EIB) {
Msg = EIB.message();
});
if (ErrStr)
*ErrStr = Msg;
// We got an error, just return 0
return nullptr;
}
return new Interpreter(std::move(M));
}
//===----------------------------------------------------------------------===//
// Interpreter ctor - Initialize stuff
//
Interpreter::Interpreter(std::unique_ptr<Module> M)
: ExecutionEngine(std::move(M)) {
memset(&ExitValue.Untyped, 0, sizeof(ExitValue.Untyped));
// Initialize the "backend"
initializeExecutionEngine();
initializeExternalFunctions();
emitGlobals();
IL = new IntrinsicLowering(getDataLayout());
}
Interpreter::~Interpreter() {
delete IL;
}
void Interpreter::runAtExitHandlers () {
while (!AtExitHandlers.empty()) {
callFunction(AtExitHandlers.back(), None);
AtExitHandlers.pop_back();
run();
}
}
/// run - Start execution with the specified function and arguments.
///
GenericValue Interpreter::runFunction(Function *F,
ArrayRef<GenericValue> ArgValues) {
assert (F && "Function *F was null at entry to run()");
// Try extra hard not to pass extra args to a function that isn't
// expecting them. C programmers frequently bend the rules and
// declare main() with fewer parameters than it actually gets
// passed, and the interpreter barfs if you pass a function more
// parameters than it is declared to take. This does not attempt to
// take into account gratuitous differences in declared types,
// though.
const size_t ArgCount = F->getFunctionType()->getNumParams();
ArrayRef<GenericValue> ActualArgs =
ArgValues.slice(0, std::min(ArgValues.size(), ArgCount));
// Set up the function call.
callFunction(F, ActualArgs);
// Start executing the function.
run();
return ExitValue;
}